Payment Gateway plugin issue

Hello
i am using Nop 4.2 with online payment gateway and it's working normally. i faced issue when i start using discount code and loyalty points  and the payment gateway plugin dose not calculate subtract the amount of discount code and loyalty point.
so i contact with support disk with payment company and the send me the source code of plugin and they say edit by your own.
can any one help me with this and I'll pay for this ?
this 2 status of issue .
i using Arabic language  but u well understand what i mean by numbers
1- when using Discount Code
https://ibb.co/GJdhqZk
https://ibb.co/nnqbXDC
https://ibb.co/Z18fwDV
https://ibb.co/grhzLs8

2- when Using loyalty Point
https://ibb.co/Nm6hKxP
https://ibb.co/h8KXYhk
https://ibb.co/LvqP5VP
https://ibb.co/LxVCrMr

Hello there!
Hope you're doing good

I can help with your requirement.

Kindly reach out to me at [email protected] or skype me at live: luis_18439.



Hope to hear from you soon.



Have a nice day.

Thanks and Regards,

esmhos wrote:

Hello,

We can definitely provide the solution for it.
Please join me on Skype: jatin.gadhiya1

We are always Glad to Serve you.

Thanks & Regards
Jatin